The present invention concerns an electronic hand-held device. More particularly, but not exclusively, the invention relates to a device comprising first and second units mounted for movement relative to each other such that the device has a first configuration in which the first unit is in a contracted position, the second unit is in a depressed position, and the upper surface of the second unit is positioned beneath the first unit, and a second configuration in which the first unit is in an extended position, the second unit is in a raised position, and the upper surfaces of the first and second units are adjacent to each other.
There are proposals in the prior art for mobile telephones having such an arrangement of units. In these proposals, the first unit is typically in the form of a slidably mounted cover. As such, these mobile telephones are typically referred to as slider phones and typically have a second unit in the form of keypad unit. The cover typically comprises a display screen. Thus, the display screen is movable to selectively reveal and conceal a keypad unit, which when revealed rises from a depressed position to a raised position so that its upper surface is adjacent to, and typically flush with, with the upper surface of the display screen.
Some slider phones of the prior art are arranged such that the keypad unit is simply sprung towards the raised position so that once the display screen unit is moved to reveal completely the keypad unit, the keypad unit is free to pop up under the action of the spring. An example of such a device is proposed in US 2005/0233785 (Samsung Electronics Co. Ltd). US 2005/0245297 (Samsung Electronics Co. Ltd) also discloses a phone with a pop-up keypad unit, wherein the movement of the pop-up keypad unit towards the raised position is dependent on the longitudinal sliding movement of an upper keypad unit. In this case a protrusion on the pop-up keypad is received by a channel connected to the upper keypad unit, such that towards the end of the movement of the upper keypad unit, the longitudinal movement of the channel causes the pop-up keypad to be raised. A problem with the devices of either US 2005/0233785 or US 2005/0245297 is that if the user exerts any significant force downwardly on the keypad there is a tendency for the keypad to move downwards, possibly causing the display screen to retract.
WO 2008/074358 (Nokia Corporation) solves the above problem associated with US 2005/0245297 by providing a device having a cam mechanism which provides a reversible locked configuration allowing a keypad to be locked in a raised position when the device is in an “in-use” position. The keypad may be unlocked to allow it to be lowered and to allow a display screen to be moved to conceal the keypad, by means of pulling the display screen to further extend it, before then allowing it to retract under the action of a spring. The cam mechanism for achieving this function includes a cam surface defining a complicated circular path followed by a guide pin such that the path followed by the guide pin when moving the device from the closed configuration to the configuration in which the keypad is locked in its raised position is different from the path followed by the guide pin when moving the device from the locked-open position to the closed configuration. Thus, whilst WO 2008/074358 provides a means of locking a keypad in a raised position, the mechanism proposed is complicated and requires the user to manipulate the device in a counter-intuitive manner in order to move the device from it locked open state to its closed state. WO 2008/074358 also proposes providing biasing means directly beneath the keypad, thereby affecting the amount of space beneath the keypad useable for other purposes.
Proposals which include suggestions of providing, beneath a pop-up keypad unit, mechanical means for biasing or guiding movement of the keypad unit suffer from further disadvantages. Providing such mechanical means beneath the keypad unit takes up valuable space that could be better utilised by other components of such devices.
Furthermore, the physical space within a hand-held electronic device is inherently limited. The space requirements for mechanisms that are used to control and/or guide movement of a display screen unit which moves away from the rest of the device when revealing the keypad unit are further restricted by the dimensions of both the display screen unit and the rest of device (particularly the dimensions in the direction of travel of the display screen unit) as a result of the changing geometry of the device as between its first and second configurations and in view of the length of travel of the display screen unit between its extreme positions.
The present invention seeks to mitigate the above-mentioned problems. Alternatively or additionally, the present invention seeks to provide an improved electronic hand-held device.